.box {
  background-color: #f4f0e5;
  width: 450px;
  height: 300px;
  position: relative;
  display: flex;
}
.box .item {
  width: 100px;
  height: 50px;
  background-color: #d9d9f4;
  transition: all 1s linear;
  color: #fff;
}
.box .item:nth-of-type(2) {
  background-color: #ceeee5;
}
.box .item:nth-of-type(3) {
  background-color: #9cd3a9;
}
.box button {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
.basis {
  flex-basis: 150px;
}
